Hi I was wondering how a Linuxbox running iproute2 and tc to do bandwidth control on a 20 mbit internet connection compares? A Packeteer PacketShaper 4500 costs about $20,000, and a Linuxbox can be set up for much less, but can it be used for a network with some 1000 users without too much trouble? Following that question, how is the latency affected by a Linux router? The PacketShaper should add no more than 50 msec pr packet, how does Linux compare to this? If someone has experience with a machine connected to an internetconnection with the same bandwidth, I would like to hear about it very much. Now, I realize that the Packeteer thing is much easier to configure, and also provides some pretty extensive statistical information, but that is not necessary for me. yours, -- Joakim Recht Tlf. 20 85 54 77 Email god@cs.auc.dk WWW http://www.braindump.dk / http://www.compuclub.dk
On Thu, Feb 01, 2001 at 07:07:19PM +0100, Joakim Recht wrote:> Hi > > I was wondering how a Linuxbox running iproute2 and tc to do bandwidth > control on a 20 mbit internet connection compares? A Packeteer > PacketShaper 4500 costs about $20,000, and a Linuxbox can be set up for > much less, but can it be used for a network with some 1000 users without > too much trouble?Number of users is not that big an issue. We''ve filtered 90mbit/s of traffic with Linux, but we currently only shape up to 5mbit/s. However, the sites we filter have >100 http connections per second, which each take a few seconds to complete, so I''d guess that at any one time we have ~300 tcp/ip sessions running. I bet a 1000 users would not come near to that amount of sessions.> Following that question, how is the latency affected by a Linux router? > The PacketShaper should add no more than 50 msec pr packet, how does > Linux compare to this?Well, AFAIK, Packeteers, which used to be quite evil wrt to corrupting IP options by the way!, ''shape'' by fooling around with TCP Window options. That does not induce a lot of latency. Regular shaping might induce more, but it hasn''t been a problem for us so far. As long as you are not actively shaping (ie, remain below your bandwidth ceiling), we don''t see *any* additional latency.> Now, I realize that the Packeteer thing is much easier to configure, and > also provides some pretty extensive statistical information, but that is > not necessary for me.We''ve only configured our shaping solution once, using the excellent CBQ.init script. Takes little time, and then runs on without any problems. Regards, bert hubert -- PowerDNS Versatile DNS Services Trilab The Technology People ''SYN! .. SYN|ACK! .. ACK!'' - the mating call of the internet
bert hubert wrote:> > Number of users is not that big an issue. We''ve filtered 90mbit/s of traffic > with Linux, but we currently only shape up to 5mbit/s. However, the sites we > filter have >100 http connections per second, which each take a few seconds > to complete, so I''d guess that at any one time we have ~300 tcp/ip sessions > running. > > I bet a 1000 users would not come near to that amount of sessions.Well, I''ve had to increase /proc/sys/net/ipv4/ip_conntrack_max from 16k to a larger value on a network with 300 users, so something tells me that quite a lot of connections are open.> > Regular shaping might induce more, but it hasn''t been a problem for us so > far. As long as you are not actively shaping (ie, remain below your > bandwidth ceiling), we don''t see *any* additional latency.This is the problem for me... The connection is to be distributed between some 8 college dorms, and the users here use quite a lot of bandwidth right now, as we are connected to a university connection. However, we are about to buy our own, which means a pretty crowded 20 mbit connection, and as each dorm should be guaranteed an amount of bandwidth, shaping could occur very often, at least at peak hours in the afternoon/evening.> We''ve only configured our shaping solution once, using the excellent > CBQ.init script. Takes little time, and then runs on without any problems. > > Regards, > > bert hubert >Thanks for your reply, -- Joakim Recht Tlf. 20 85 54 77 Email god@cs.auc.dk WWW http://www.braindump.dk / http://www.compuclub.dk